Photocatalytic Degradation of Organic Dyes

For the photocatalytic degradation study, three dyes were selected such as Orange G, Acid Blue 161, and Brillant Green. To eliminate the maximum dye level, a Pen‐Ray UV (ColeParmer) lamp with a wavelength of 254 nm and a light intensity of 44 W m⁻² was used. The saturated oxygen concentration in the solution medium was achieved with the help of a pump. Experiments were made by adding 100 mg of photocatalyst to a 20 mg L⁻¹ dye solution with a volume of 400 mL. Before starting the experiments, they were mixed for 30 min in the dark for the adsorption and desorption of dye molecules on the surface of the photocatalysis. Samples taken at different time intervals were centrifuged to determine the concentration. The concentration of the samples was measured at wavelengths of 578, 624, and 475 nm using a UV spectrophotometer (Optizen α). Table 1 shows the molecular properties of Brilliant Green, Acid Blue 161, and Orange G dyes. Decomposition percentages of Acid Blue 161, Brilliant Green, and Orange G dyestuffs before and after photocatalytic degradation were calculated using Equation 1.
$$\mathrm{Percentage}\mathrm{of}\mathrm{degradation}\%=\left(C_0-C_{\mathrm{s}}/C_0\right)\times 100$$
C₀ and C_s represent the initial and final dye concentrations in the aqueous phase, respectively.